/*
- * Copyright (C) 2011 - David Goulet <dgoulet@efficios.com>
- * 2014 - Jan Glauber <jan.glauber@gmail.com>
+ * Copyright (C) 2011 David Goulet <dgoulet@efficios.com>
+ * Copyright (C) 2014 Jan Glauber <jan.glauber@gmail.com>
*
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License, version 2 only,
- * as published by the Free Software Foundation.
+ * SPDX-License-Identifier: GPL-2.0-only
*
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
+ */
+
+/**
+ * @file modprobe.c
+ *
+ * @brief modprobe related functions.
*
- * You should have received a copy of the GNU General Public License along
- * with this program; if not, write to the Free Software Foundation, Inc.,
- * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
-#define _GNU_SOURCE
#define _LGPL_SOURCE
#include <assert.h>
#include <stdio.h>
#include "modprobe.h"
#include "kern-modules.h"
+#include "lttng-sessiond.h"
#define LTTNG_MOD_REQUIRED 1
#define LTTNG_MOD_OPTIONAL 0
/* LTTng kernel tracer mandatory core modules list */
struct kern_modules_param kern_modules_control_core[] = {
- { "lttng-tracer" }, /* MUST be loaded first so keep at top */
- { "lttng-lib-ring-buffer" },
- { "lttng-ring-buffer-client-discard" },
- { "lttng-ring-buffer-client-overwrite" },
- { "lttng-ring-buffer-metadata-client" },
- { "lttng-ring-buffer-client-mmap-discard" },
- { "lttng-ring-buffer-client-mmap-overwrite" },
- { "lttng-ring-buffer-metadata-mmap-client" },
-};
-
-/* LTTng kernel tracer optional base modules list */
-struct kern_modules_param kern_modules_control_opt[] = {
- { "lttng-types" },
- { "lttng-ftrace" },
- { "lttng-kprobes" },
- { "lttng-kretprobes" },
+ { (char *) "lttng-ring-buffer-client-discard" },
+ { (char *) "lttng-ring-buffer-client-overwrite" },
+ { (char *) "lttng-ring-buffer-metadata-client" },
+ { (char *) "lttng-ring-buffer-client-mmap-discard" },
+ { (char *) "lttng-ring-buffer-client-mmap-overwrite" },
+ { (char *) "lttng-ring-buffer-metadata-mmap-client" },
};
/* LTTng kernel tracer probe modules list */
struct kern_modules_param kern_modules_probes_default[] = {
- { "lttng-probe-asoc" },
- { "lttng-probe-block" },
- { "lttng-probe-btrfs" },
- { "lttng-probe-compaction" },
- { "lttng-probe-ext3" },
- { "lttng-probe-ext4" },
- { "lttng-probe-gpio" },
- { "lttng-probe-irq" },
- { "lttng-probe-jbd" },
- { "lttng-probe-jbd2" },
- { "lttng-probe-kmem" },
- { "lttng-probe-kvm" },
- { "lttng-probe-kvm-x86" },
- { "lttng-probe-kvm-x86-mmu" },
- { "lttng-probe-lock" },
- { "lttng-probe-module" },
- { "lttng-probe-napi" },
- { "lttng-probe-net" },
- { "lttng-probe-power" },
- { "lttng-probe-printk" },
- { "lttng-probe-random" },
- { "lttng-probe-rcu" },
- { "lttng-probe-regmap" },
- { "lttng-probe-regulator" },
- { "lttng-probe-rpm" },
- { "lttng-probe-sched" },
- { "lttng-probe-scsi" },
- { "lttng-probe-signal" },
- { "lttng-probe-skb" },
- { "lttng-probe-sock" },
- { "lttng-probe-statedump" },
- { "lttng-probe-sunrpc" },
- { "lttng-probe-timer" },
- { "lttng-probe-udp" },
- { "lttng-probe-vmscan" },
- { "lttng-probe-v4l2" },
- { "lttng-probe-workqueue" },
- { "lttng-probe-writeback" },
+ { (char *) "lttng-probe-asoc" },
+ { (char *) "lttng-probe-block" },
+ { (char *) "lttng-probe-btrfs" },
+ { (char *) "lttng-probe-compaction" },
+ { (char *) "lttng-probe-ext3" },
+ { (char *) "lttng-probe-ext4" },
+ { (char *) "lttng-probe-gpio" },
+ { (char *) "lttng-probe-i2c" },
+ { (char *) "lttng-probe-irq" },
+ { (char *) "lttng-probe-jbd" },
+ { (char *) "lttng-probe-jbd2" },
+ { (char *) "lttng-probe-kmem" },
+ { (char *) "lttng-probe-kvm" },
+ { (char *) "lttng-probe-kvm-x86" },
+ { (char *) "lttng-probe-kvm-x86-mmu" },
+ { (char *) "lttng-probe-lock" },
+ { (char *) "lttng-probe-module" },
+ { (char *) "lttng-probe-napi" },
+ { (char *) "lttng-probe-net" },
+ { (char *) "lttng-probe-power" },
+ { (char *) "lttng-probe-preemptirq" },
+ { (char *) "lttng-probe-printk" },
+ { (char *) "lttng-probe-random" },
+ { (char *) "lttng-probe-rcu" },
+ { (char *) "lttng-probe-regmap" },
+ { (char *) "lttng-probe-regulator" },
+ { (char *) "lttng-probe-rpm" },
+ { (char *) "lttng-probe-sched" },
+ { (char *) "lttng-probe-scsi" },
+ { (char *) "lttng-probe-signal" },
+ { (char *) "lttng-probe-skb" },
+ { (char *) "lttng-probe-sock" },
+ { (char *) "lttng-probe-statedump" },
+ { (char *) "lttng-probe-sunrpc" },
+ { (char *) "lttng-probe-timer" },
+ { (char *) "lttng-probe-udp" },
+ { (char *) "lttng-probe-vmscan" },
+ { (char *) "lttng-probe-v4l2" },
+ { (char *) "lttng-probe-workqueue" },
+ { (char *) "lttng-probe-writeback" },
+ { (char *) "lttng-probe-x86-irq-vectors" },
+ { (char *) "lttng-probe-x86-exceptions" },
};
/* dynamic probe modules list */
static int nr_probes;
static int probes_capacity;
-static void modprobe_remove_lttng(const struct kern_modules_param *modules,
- int entries, int required)
-{
- int ret = 0, i;
- char modprobe[256];
-
- for (i = entries - 1; i >= 0; i--) {
- ret = snprintf(modprobe, sizeof(modprobe),
- "/sbin/modprobe -r -q %s",
- modules[i].name);
- if (ret < 0) {
- PERROR("snprintf modprobe -r");
- return;
- }
- modprobe[sizeof(modprobe) - 1] = '\0';
- ret = system(modprobe);
- if (ret == -1) {
- ERR("Unable to launch modprobe -r for module %s",
- modules[i].name);
- } else if (required && WEXITSTATUS(ret) != 0) {
- ERR("Unable to remove module %s",
- modules[i].name);
- } else {
- DBG("Modprobe removal successful %s",
- modules[i].name);
- }
- }
-}
-
-/*
- * Remove control kernel module(s) in reverse load order.
- */
-void modprobe_remove_lttng_control(void)
-{
- modprobe_remove_lttng(kern_modules_control_opt,
- ARRAY_SIZE(kern_modules_control_opt),
- LTTNG_MOD_OPTIONAL);
- modprobe_remove_lttng(kern_modules_control_core,
- ARRAY_SIZE(kern_modules_control_core),
- LTTNG_MOD_REQUIRED);
-}
-
-/*
- * Remove data kernel modules in reverse load order.
- */
-void modprobe_remove_lttng_data(void)
-{
- int i;
-
- if (probes) {
- modprobe_remove_lttng(probes, nr_probes, LTTNG_MOD_OPTIONAL);
-
- for (i = 0; i < nr_probes; ++i) {
- free(probes[i].name);
- }
-
- free(probes);
- probes = NULL;
- }
-}
-
-/*
- * Remove all kernel modules in reverse order.
- */
-void modprobe_remove_lttng_all(void)
-{
- modprobe_remove_lttng_data();
- modprobe_remove_lttng_control();
-}
-
#if HAVE_KMOD
#include <libkmod.h>
+
+/**
+ * @brief Logging function for libkmod integration.
+ */
static void log_kmod(void *data, int priority, const char *file, int line,
const char *fn, const char *format, va_list args)
{
DBG("libkmod: %s", str);
free(str);
}
-static int modprobe_lttng(struct kern_modules_param *modules,
- int entries, int required)
+
+/**
+ * @brief Setup the libkmod context.
+ *
+ * Create the context, add a custom logging function and preload the
+ * ressources for faster operation.
+ *
+ * @returns \c 0 on success
+ * \c < 0 on error
+ */
+static int setup_kmod_ctx(struct kmod_ctx **ctx)
{
- int ret = 0, i;
- struct kmod_ctx *ctx;
+ int ret = 0;
- ctx = kmod_new(NULL, NULL);
+ *ctx = kmod_new(NULL, NULL);
if (!ctx) {
PERROR("Unable to create kmod library context");
ret = -ENOMEM;
goto error;
}
- kmod_set_log_fn(ctx, log_kmod, NULL);
- kmod_load_resources(ctx);
+ kmod_set_log_fn(*ctx, log_kmod, NULL);
+ ret = kmod_load_resources(*ctx);
+ if (ret < 0) {
+ ERR("Failed to load kmod library resources");
+ goto error;
+ }
+
+error:
+ return ret;
+}
+
+/**
+ * @brief Loads the kernel modules in \p modules
+ *
+ * @param modules List of modules to load
+ * @param entries Number of modules in the list
+ * @param required Are the modules required or optionnal
+ *
+ * If the modules are required, we will return with error after the
+ * first failed module load, otherwise we continue loading.
+ *
+ * @returns \c 0 on success
+ * \c < 0 on error
+ */
+static int modprobe_lttng(struct kern_modules_param *modules,
+ int entries, int required)
+{
+ int ret = 0, i;
+ struct kmod_ctx *ctx;
+
+ ret = setup_kmod_ctx(&ctx);
+ if (ret < 0) {
+ goto error;
+ }
for (i = 0; i < entries; i++) {
struct kmod_module *mod = NULL;
goto error;
}
- ret = kmod_module_probe_insert_module(mod, KMOD_PROBE_IGNORE_LOADED,
+ ret = kmod_module_probe_insert_module(mod, 0,
NULL, NULL, NULL, NULL);
- if (ret < 0) {
+ if (ret == -EEXIST) {
+ DBG("Module %s is already loaded", modules[i].name);
+ ret = 0;
+ } else if (ret < 0) {
if (required) {
ERR("Unable to load required module %s",
modules[i].name);
}
} else {
DBG("Modprobe successfully %s", modules[i].name);
+ modules[i].loaded = true;
}
kmod_module_unref(mod);
return ret;
}
+/**
+ * @brief Recursively unload modules.
+ *
+ * This function implements the same modules unloading behavior as
+ * 'modprobe -r' or rmmod, it will recursevily go trought the \p module
+ * dependencies and unload modules with a refcount of 0.
+ *
+ * @param mod The module to unload
+ *
+ * @returns \c 0 on success
+ * \c < 0 on error
+ */
+static int rmmod_recurse(struct kmod_module *mod) {
+ int ret = 0;
+ struct kmod_list *deps, *itr;
+
+ if (kmod_module_get_initstate(mod) == KMOD_MODULE_BUILTIN) {
+ DBG("Module %s is builtin", kmod_module_get_name(mod));
+ return ret;
+ }
+
+ ret = kmod_module_remove_module(mod, 0);
+
+ deps = kmod_module_get_dependencies(mod);
+ if (deps != NULL) {
+ kmod_list_foreach(itr, deps) {
+ struct kmod_module *dep = kmod_module_get_module(itr);
+ if (kmod_module_get_refcnt(dep) == 0) {
+ DBG("Recursive remove module %s",
+ kmod_module_get_name(dep));
+ rmmod_recurse(dep);
+ }
+ kmod_module_unref(dep);
+ }
+ kmod_module_unref_list(deps);
+ }
+
+ return ret;
+}
+
+/**
+ * @brief Unloads the kernel modules in \p modules
+ *
+ * @param modules List of modules to unload
+ * @param entries Number of modules in the list
+ * @param required Are the modules required or optionnal
+ *
+ */
+static void modprobe_remove_lttng(const struct kern_modules_param *modules,
+ int entries, int required)
+{
+ int ret = 0, i;
+ struct kmod_ctx *ctx;
+
+ ret = setup_kmod_ctx(&ctx);
+ if (ret < 0) {
+ goto error;
+ }
+
+ for (i = entries - 1; i >= 0; i--) {
+ struct kmod_module *mod = NULL;
+
+ if (!modules[i].loaded) {
+ continue;
+ }
+
+ ret = kmod_module_new_from_name(ctx, modules[i].name, &mod);
+ if (ret < 0) {
+ PERROR("Failed to create kmod module for %s", modules[i].name);
+ goto error;
+ }
+
+ ret = rmmod_recurse(mod);
+ if (ret == -EEXIST) {
+ DBG("Module %s is not in kernel.", modules[i].name);
+ } else if (required && ret < 0) {
+ ERR("Unable to remove module %s", modules[i].name);
+ } else {
+ DBG("Modprobe removal successful %s",
+ modules[i].name);
+ }
+
+ kmod_module_unref(mod);
+ }
+
+error:
+ if (ctx) {
+ kmod_unref(ctx);
+ }
+}
+
#else /* HAVE_KMOD */
static int modprobe_lttng(struct kern_modules_param *modules,
}
} else {
DBG("Modprobe successfully %s", modules[i].name);
+ modules[i].loaded = true;
}
}
return ret;
}
+static void modprobe_remove_lttng(const struct kern_modules_param *modules,
+ int entries, int required)
+{
+ int ret = 0, i;
+ char modprobe[256];
+
+ for (i = entries - 1; i >= 0; i--) {
+ if (!modules[i].loaded) {
+ continue;
+ }
+ ret = snprintf(modprobe, sizeof(modprobe),
+ "/sbin/modprobe -r -q %s",
+ modules[i].name);
+ if (ret < 0) {
+ PERROR("snprintf modprobe -r");
+ return;
+ }
+ modprobe[sizeof(modprobe) - 1] = '\0';
+ ret = system(modprobe);
+ if (ret == -1) {
+ ERR("Unable to launch modprobe -r for module %s",
+ modules[i].name);
+ } else if (required && WEXITSTATUS(ret) != 0) {
+ ERR("Unable to remove module %s",
+ modules[i].name);
+ } else {
+ DBG("Modprobe removal successful %s",
+ modules[i].name);
+ }
+ }
+}
+
#endif /* HAVE_KMOD */
+/*
+ * Remove control kernel module(s) in reverse load order.
+ */
+void modprobe_remove_lttng_control(void)
+{
+ modprobe_remove_lttng(kern_modules_control_core,
+ ARRAY_SIZE(kern_modules_control_core),
+ LTTNG_MOD_REQUIRED);
+}
+
+static void free_probes(void)
+{
+ int i;
+
+ if (!probes) {
+ return;
+ }
+ for (i = 0; i < nr_probes; ++i) {
+ free(probes[i].name);
+ }
+ free(probes);
+ probes = NULL;
+ nr_probes = 0;
+}
+
+/*
+ * Remove data kernel modules in reverse load order.
+ */
+void modprobe_remove_lttng_data(void)
+{
+ if (!probes) {
+ return;
+ }
+ modprobe_remove_lttng(probes, nr_probes, LTTNG_MOD_OPTIONAL);
+ free_probes();
+}
+
+/*
+ * Remove all kernel modules in reverse order.
+ */
+void modprobe_remove_lttng_all(void)
+{
+ modprobe_remove_lttng_data();
+ modprobe_remove_lttng_control();
+}
+
/*
* Load control kernel module(s).
*/
ret = modprobe_lttng(kern_modules_control_core,
ARRAY_SIZE(kern_modules_control_core),
LTTNG_MOD_REQUIRED);
- if (ret != 0)
- return ret;
- ret = modprobe_lttng(kern_modules_control_opt,
- ARRAY_SIZE(kern_modules_control_opt),
- LTTNG_MOD_OPTIONAL);
return ret;
}
static int append_list_to_probes(const char *list)
{
char *next;
- int index = nr_probes, ret;
+ int ret;
+ char *tmp_list, *cur_list;
assert(list);
- char *tmp_list = strdup(list);
+ cur_list = tmp_list = strdup(list);
if (!tmp_list) {
PERROR("strdup temp list");
return -ENOMEM;
size_t name_len;
struct kern_modules_param *cur_mod;
- next = strtok(tmp_list, ",");
+ next = strtok(cur_list, ",");
if (!next) {
break;
}
- tmp_list = NULL;
+ cur_list = NULL;
/* filter leading spaces */
while (*next == ' ') {
if (probes_capacity <= nr_probes) {
ret = grow_probes();
if (ret) {
- return ret;
+ goto error;
}
}
/* Length 13 is "lttng-probe-" + \0 */
name_len = strlen(next) + 13;
- cur_mod = &probes[index];
+ cur_mod = &probes[nr_probes];
cur_mod->name = zmalloc(name_len);
if (!cur_mod->name) {
PERROR("malloc probe list");
- return -ENOMEM;
+ ret = -ENOMEM;
+ goto error;
}
ret = snprintf(cur_mod->name, name_len, "lttng-probe-%s", next);
if (ret < 0) {
PERROR("snprintf modprobe name");
- return -ENOMEM;
+ ret = -ENOMEM;
+ goto error;
}
- cur_mod++;
nr_probes++;
}
free(tmp_list);
-
return 0;
+
+error:
+ free(tmp_list);
+ free_probes();
+ return ret;
}
/*
* Base probes: either from command line option, environment
* variable or default list.
*/
- if (kmod_probes_list) {
- list = kmod_probes_list;
- } else {
- list = utils_get_kmod_probes_list();
- }
-
+ list = config.kmod_probes_list.value;
if (list) {
/* User-specified probes. */
ret = append_list_to_probes(list);
-
if (ret) {
return ret;
}
} else {
/* Default probes. */
int def_len = ARRAY_SIZE(kern_modules_probes_default);
- probes = zmalloc(sizeof(*probes) * def_len);
+ probes = zmalloc(sizeof(*probes) * def_len);
if (!probes) {
PERROR("malloc probe list");
return -ENOMEM;
if (!name) {
PERROR("strdup probe item");
- return -ENOMEM;
+ ret = -ENOMEM;
+ goto error;
}
probes[i].name = name;
/*
* Extra modules? Append them to current probes list.
*/
- if (kmod_extra_probes_list) {
- list = kmod_extra_probes_list;
- } else {
- list = utils_get_extra_kmod_probes_list();
- }
-
+ list = config.kmod_extra_probes_list.value;
if (list) {
ret = append_list_to_probes(list);
if (ret) {
- return ret;
+ goto error;
}
}
/*
* Load probes modules now.
*/
- return modprobe_lttng(probes, nr_probes, LTTNG_MOD_OPTIONAL);
+ ret = modprobe_lttng(probes, nr_probes, LTTNG_MOD_OPTIONAL);
+ if (ret) {
+ goto error;
+ }
+ return ret;
+
+error:
+ free_probes();
+ return ret;
}